I have a friend with whom I can't play. We can't even connect in private chat or an XBL party. Sometimes it works, but most of the time it doesn't unless one of us has another friend present. He can play just fine with all of his other friends, as can I, we just can't seem to play with each other. My NAT is set to open, but prior to the purchase of a router, it was strict (was plugged directly into an ethernet outlet). We were having this problem then and thought it was the ethernet/strict NAT setting. The XBox is plugged in to the router now, since I don't have wireless capabilities. My friend uses his phone to connect online. Any suggestions on how to remedy this or why it's happening? It doesn't make sense, since I'm the only person he can't connect with, and vice versa. Thanks!!